The royal waiting game. When the new heir is born, there will be a royal route for the announcement. Amy robach is there at the begins of the ruth outside st. Mary's hospital. Good evening, amy. Reporter: That's right. The lindo wing here at st. Mary's hospital has been affectionately named the "limbo" wing by the press who have been anxiously awaiting the arrival of the newest royal for weeks. Journalists from around the world are marking the days and their territory. I'll be setting up my spot just around here somewhere. You're stepping on people's spots. Reporter: All waiting for the moment when william and kate walk out these doors with a swaddled future monarch. But what to do with all of the hours until that moment? Sami al-zaid was one of the first journalists to camp outside the hospital. That was nearly three weeks ago. We snapped a photo of him way back when he was on his first book. So you're on book number four now? Yes. You're getting a lot of quality reading in. I'm going for six. Reporter: In this day of instant technology, the framed paper birth announcement will be handed to a waiting driver and make its way 2.1 miles through the streets of london from st. Mary's hospital to buckingham palace with a police escort. According to tradition, the announcement will be brought to the front of the palace by a liveried footman who will hand it to the queen's press secretary, who will then place the bulletin on the easel -- the very easel last used to announce prince william's birth. And we know the announcement cannot happen while the queen is asleep. And she does not want to be woken up? We have been told that until her majesty knows about this heir, the rest of us will no nothing whatsoever. Reporter: And there's the issue then of naming the baby. If we look back at history, it could take a monthr a matter of hours. Prince charles, four weeks after he was born we learned his name. One week for prince william. 24 hours for prince harry.

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